Why make the villains sympathetic?

[Rorick]

Yes, you're right. What I meant was that, they see their course of action as the correct one. Things like people getting hurt being a bad thing are, after all, social constructs, and not all societies and civilisations have shared that world view.

You're also correct in that they don't necessarily have to be ignorant of their wrongs, absolutely. The point still stands though that unless you can convince the reader that the antagonist believes what they are doing is justified, by whatever skewed world view, your protagonist isn't going to be believable.

 

[T.Allen.Smith]

I think sympathetic is probably the wrong word. Empathy is probably more correct in my opinion. Sympathy implies you understand and accept the motivations. I think you just have to ensure the reader can understand why an antagonist has taken the actions she has taken, not necessarily agree with them.

I understand where you're coming from concerning the meaning of the word. However, in "writing craft" terms, the word sympathy refers to traits & other aspects of character (like special skills, relationships with other characters, etc.) that make the character real, interesting, and in even some small way relatable for the reader. It doesn't mean that we condone the action.

In terms of word meaning alone though, I can certainly have sympathy for someone without condoning their ideals or actions. Empathy is the ability to understand or the ability to enter into another's feelings or state of mind, and in that way come to an understanding.